Smilodon
Smilodon ( /ˈsmaɪlədɒn/), often called a saber-toothed cat or incorrectly a saber-toothed tiger, is an extinct genus of machairodonts.[2] This saber-toothed cat was endemic to North America and South America, living from near the beginning through the very end of the Pleistocene epoch (2.5 mya—10,000 years ago). The nickname "saber-tooth" refers to the extreme length of their maxillary canines. Despite the colloquial name "saber-toothed tiger", Smilodon is not a tiger; the latter belongs to subfamily Pantherinae, whereas Smilodon belongs to subfamily Machairodontinae. Smilodon fatalis, 1.6 million-10,000 years ago, replaced Smilodon gracilis in North America and invaded western South America as part of the Great American Interchange. In size it was between Smilodon gracilis and Smilodon populator, and about the same as the largest surviving cat, the Siberian tiger. This species was about 1 m high at the shoulder and is estimated to have ranged from 160 to 280 kg (350 to 620 lb). Sometimes two additional species are recognized, Smilodon californicus and Smilodon floridanus, but usually they are considered to be subspecies of Smilodon fatalis. Smilodon had relatively shorter and more massive limbs than other felines. It had well developed flexors and extensors in its forepaws, which enabled it to pull down large prey. The back limbs had powerfully built adductor muscles which might have helped the cat's stability when wrestling with prey. Like most cats, its claws were retractable. Smilodon is most famous for its relatively long canines, which are the longest found in the saber-toothed cats, at about 28 cm (11 in) long in the largest species Smilodon populator. These canine teeth were fragile and could not have bitten into bone; thus, these cats did not use their long teeth while taking down prey, due to the risk of breaking them. Only when their prey was totally subdued did they use their teeth to simultaneously sever the blood supply and strangle the windpipe, instantly killing the prey. Despite being more powerfully built than other large cats, Smilodon actually had a weaker bite. Modern big cats have more pronounced zygomatic arches, while Smilodon had smaller zygomatic arches which restricted the thickness and therefore power of the temporalis muscles, and thus reduced Smilodon’s bite force. Analysis of its narrow jaws indicates it could produce a bite only a third as strong as that of a lion. There seems to a be a general rule that the saber-toothed cats with the largest canines had proportionally weaker bites. However, analyses of canine bending strength (the ability of the canine teeth to resist bending forces without breaking) and bite forces indicate the saber-toothed cats' teeth were stronger relative to the bite force than those of modern "big cats". In addition, Smilodon could open its jaws 120 degrees, whereas the lion's gape is limited to 60 degrees. Smilodon probably preyed on a wide variety of large game including bison, tapirs, deer, American camels, horses and ground sloths. As it is known for the saber-toothed cat Homotherium, Smilodon might have also killed juvenile mastodons and mammoths. Smilodon may also have attacked prehistoric humans, although this is not known for certain. The La Brea tar pits in California trapped hundreds of Smilodon in the tar, possibly as they tried to feed on mammoths already trapped. The Natural History Museum of Los Angeles County has many of their complete skeletons. Category:Animals Category:Mammals Category:Felids Category:Carnivores Category:Vertebrates Category:Prehistoric animals Category:North American Animals Category:South American Animals Category:Central American Animals